# RigidbodyFPSWalker

## Description

This is a rigidbody based first person controller. Traditionally first person controllers are done using the character controller and this is the recommended way, but sometimes you want it to use real physics. So forces automatically affect the rigidbody, and joints can be used to eg. make a rope swinging game.

The script works by adding a force in the direction of desired movement, it subtracts the current velocity from it, thus when letting go of all keys the character will stop. A maximum velocity change can be specified which will make the character come to reset slower faster and in effect apply more or less force to object the character runs into.

## JavaScript - RigidbodyFPSController.js

```var speed = 10.0;
var gravity = 10.0;
var maxVelocityChange = 10.0;
var canJump = true;
var jumpHeight = 2.0;
private var grounded = false;

@script RequireComponent(Rigidbody, CapsuleCollider)

function Awake ()
{
rigidbody.freezeRotation = true;
rigidbody.useGravity = false;
}

function FixedUpdate ()
{
if (grounded)
{
// Calculate how fast we should be moving
var targetVelocity = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
targetVelocity = transform.TransformDirection(targetVelocity);
targetVelocity *= speed;

// Apply a force that attempts to reach our target velocity
var velocity = rigidbody.velocity;
var velocityChange = (targetVelocity - velocity);
velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
velocityChange.y = 0;

// Jump
if (canJump && Input.GetButton("Jump"))
{
rigidbody.velocity = Vector3(velocity.x, CalculateJumpVerticalSpeed(), velocity.z);
}
}

// We apply gravity manually for more tuning control
rigidbody.AddForce(Vector3 (0, -gravity * rigidbody.mass, 0));

grounded = false;
}

function OnCollisionStay ()
{
grounded = true;
}

function CalculateJumpVerticalSpeed ()
{
// From the jump height and gravity we deduce the upwards speed
// for the character to reach at the apex.
return Mathf.Sqrt(2 * jumpHeight * gravity);
}```

## C# - RigidbodyFPSController.cs

```using UnityEngine;
using System.Collections;

[RequireComponent (typeof (Rigidbody))]
[RequireComponent (typeof (CapsuleCollider))]

public class CharacterControls : MonoBehaviour {

public float speed = 10.0f;
public float gravity = 10.0f;
public float maxVelocityChange = 10.0f;
public bool canJump = true;
public float jumpHeight = 2.0f;
private bool grounded = false;

void Awake () {
rigidbody.freezeRotation = true;
rigidbody.useGravity = false;
}

void FixedUpdate () {
if (grounded) {
// Calculate how fast we should be moving
Vector3 targetVelocity = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
targetVelocity = transform.TransformDirection(targetVelocity);
targetVelocity *= speed;

// Apply a force that attempts to reach our target velocity
Vector3 velocity = rigidbody.velocity;
Vector3 velocityChange = (targetVelocity - velocity);
velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
velocityChange.y = 0;

// Jump
if (canJump && Input.GetButton("Jump")) {
rigidbody.velocity = new Vector3(velocity.x, CalculateJumpVerticalSpeed(), velocity.z);
}
}

// We apply gravity manually for more tuning control
rigidbody.AddForce(new Vector3 (0, -gravity * rigidbody.mass, 0));

grounded = false;
}

void OnCollisionStay () {
grounded = true;
}

float CalculateJumpVerticalSpeed () {
// From the jump height and gravity we deduce the upwards speed
// for the character to reach at the apex.
return Mathf.Sqrt(2 * jumpHeight * gravity);
}
}```